test(cli): migrate the _open references — closed twins for sweeps, fixtures for open semantics (closes #248)

The references to the relocated _open blueprints follow the plan's
two-way split: tests that only need a sweepable blueprint sweep the
closed twins via bound-override axes (#246) with their axis strings
byte-unchanged (the wrap prefix is the blueprint's internal name,
identical across twins); the 12 tests that genuinely exercise
open-param semantics (run/mc closed-guard refusals, subset-axes
MissingKnob, --list-axes open/bound line mix, gang dissolution and
campaign paths) read the fixtures under tests/fixtures/. The
research_docs/project_load store seeds sweep the closed twin (campaign
axis references resolve via the #246 reopen path); the INDEX.md history
note records the relocation.

Two deviations from the plan, both verified against the tree: doc
comments referencing the bare filename (no examples/ prefix) escaped
the global path swap and were reworded to stay truthful; the seed
variable open_bp was renamed closed_bp (the plan kept it, but the
rename touches only the binding and its uses and removes a
misdescription).

Verification: cargo test -p aura-cli --test cli_run (140 passed, 0
failed, real data exercised); --test research_docs; --test
project_load; the four byte-pinned exact grades unchanged; grep-clean
for examples/r_*_open.json across crates+docs; full workspace suite
green.

docs/design/INDEX.md

@@ -1032,7 +1032,8 @@ SQN comparability. Each swept member's manifest records the fixed R-defining par
 beside the floated knobs (reproducible from its own manifest, C18).
 [HISTORY — the built-in `--strategy` sweep surface was retired with the demos →
 blueprint-data (#159, cuts 1b-4); the rankable R sweep now runs as `aura sweep
-<blueprint.json> --axis …` over examples/r_sma_open.json.]
+<blueprint.json> --axis …` over r_sma_open.json (an example then; relocated to
+`crates/aura-cli/tests/fixtures/` by #248).]
 
 **Realization (cycle 0067, #130 + #135).** **#130 (SQN100):** `RMetrics` gains
 `sqn_normalized = (mean_R/stdev_R)·√(min(n, 100))` — the n-normalized "SQN score"